Air-ejector of steam-condensing plants



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tors of Steam-Condensing UNITED- STATES PIENT OFFICE.

CHAR-LES RUSSELL-LANG, on GLASGOW, sooriiannnssrenon To a; a I. want IiIMITED, on GLASGOW, soornnnn. l

AIR-EJEGTOR OF STEAM COIIDENSING' PLANT S;

Specification of Letters Patent.

Patented Mar. 22, 1921.

Application filed July 17, 1919. Serial No. 311,586.

To all whom it may concern y Be it known that I, CHARLES Itussnui LANG, a subject of the King of Great Britain and Ireland, residing at (Jathcart, Glasgow, Scotland, have invented certain new and useful Improvements Relating to Air-Ejechereby declare the following to be a full, clear, and exact description of the inven tion, such as will enable others skilled in the art to which it appertains to make and use the same, reference panying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to steam-condensing and feed water systems for steamships of the nature of those described in the specifications of Patents Nos. 1302256 and 1302257, granted April 29, 1919, e. to sys tems in which the air is withdrawn from the main condenser by a steam-jet ejector, the discharge from the ejector being delivered into a surface feed water heater where the steami. 6. both the actuating steam and the vapor drawn from the condenser with the air-is condensed, and the condensate passed into the feed system, while the heat obtained by the condensation of the steam is employed to heat the feed water which acts as condensing water in the feed heater. The feed heater is, as regards its at atmospheric or superatmospheric pressure so that, with a high vacuum in the condenser, the ejector works with a high pressure ratio.

My present invention relates particularly to the air ejector employed as above mentioned-in such systems.

I have found by investigation and research that an advantage is obtained by employing a two-stage ejector, c. e. arranging the ejector with two steam jets-or groups of parallel jets-in series, and in using highpressure steam as actuating fluid in the first stage jet and low-pressure steam as actuating fluid in the second-stage jet.

I have found out that with a high pressure ratio in the ejector such as is usual I obtain, by the use of high-pressure steam in the first-stage and low-pressure steam in the second stage, a greater economy in the whole feed system than is possible by employing high-pressure steam in both stages; while the employment of low-pressure steam Plants; and I do being hadto the accom in both stages would result in a greatly increased steam consumption whlch would necessitate a considerable increase in the cooling surface of the feed heater which condenses the steam.

Therefore, on consideringjointly the first cost of the plant, the weight and bulk of the same, and th e economy of working, I have found a distinct advantage in favor of employing high pressure steam as the im-.

pelling fluid for the jet or jets of the first stage, and low pressure steam as" the impelhng fluid for the jet or jets of the second stage, and my present invention-which will be described in the following specification and more particularly defined in the annexed claims-has reference to this employment of high and low pressure steam in the two stages.

By high-pressure steam I mean steam at a pressure not less than one hundred pounds per square inch above atmosphere. By lowpressure steam I mean steam at a pressure of from atmosphere to thirty pounds per square inch above atmosphere.

In the accompanying drawing which illustrates the carrying of the invention into effect in a convenient manner, the highpressure steam-jet is shown at a; it is fed wlth high-pressure steam by the pipe 6. The jet is centrally-situated at the suction end of the ejector-tube b. An air-inlet port 18 shown at a controlled by a valve g; this port communicates with the condenser.

A conduit 0? fed by low-pressure steam enters the tube which is enlarged at the point of entry of d. That part of the conduit which lies within the tube 1) is shaped to provide a cone h the apex of which is situated co-axially with the jet a. An annular passage 7 is provided between this part of the conduit and the tube 1) except at the point where the conduit extends through the wall of the tube. The conduit carries a ring of nozzles 70 which aredirected along the tube 6; and centrally situated in this ring of nozzles is a stream-line filling-piece m. l

The tube 5 delivers into the feed water system of the ship for the recovery of water obtained by the condensation of the steam of the jetsa, 7c, and the vapor drawn from the condenser.

Obviously instead of one high-pressure jet a, two or more may be employed, and, instead of the ring of jets in, a single jet,

within the tube and fed with steam, a hollow cone in alinement with the said nozzle and adapted to spread the impelllng charge, a steam passage in communication with the hollow cone and fed with low-pressure steam and outlet nozzles concentrically arranged at the base of the cone for ejecting the contents with, and in the direction of motion of the first named impelling charge.

2. In steam condensing and feed-water systems for steamships the combination with a main condenser, of a two-stage steam-jet ejector for withdrawing the air from the condenser comprising a tube communicating with the condenser by way of a valve, an impelling steam jet nozzle arranged axially within the tube and fed with high pressure steam, a hollow cone in alinement with the said nozzle and adapted to spread the impelling charge, a steam passage in communication with the hollow cone and fed with low-pressure steam and outlet nozzles concentrically arranged at the base of the cone for ejecting the contents with, and in the direction of motion of the first named impelling charge and a second solid cone having its base adjacent the first named hollow cone adapted to bring together the two impelling charges.

I hereby sign my name to this specification.

CHARLES RUSSELL LANG. 

